| Message ID | 1480331524-18741-5-git-send-email-wxt@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Nov 28, 2016 at 07:12:03PM +0800, Caesar Wang wrote: > In order to support the valid temperature can conver to analog value. > The rockchip thermal driver has not supported the all valid temperature > to convert the analog value. (e.g.: 61C, 62C, 63C....) > > For example: > In some cases, we need adjust the trip point. > $cd /sys/class/thermal/thermal_zone* > $echo 68000 > trip_point_0_temp > That will return the max analogic value indicates the invalid before > posting this patch. > > So, this patch will optimize the conversion table to support the other > cases. > > Signed-off-by: Caesar Wang <wxt@rock-chips.com> > Reviewed-by: Brian Norris <briannorris@chromium.org> > --- > > Changes in v3: None > Changes in v2: > - improve the commit as Brian commnets on https://patchwork.kernel.org/patch/9440985 > > Changes in v1: None > > drivers/thermal/rockchip_thermal.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c > index ca1730e..660ed3b 100644 > --- a/drivers/thermal/rockchip_thermal.c > +++ b/drivers/thermal/rockchip_thermal.c > @@ -401,6 +401,8 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, > int temp) > { > int high, low, mid; > + unsigned long num; > + unsigned int denom; > u32 error = table->data_mask; > > low = 0; > @@ -421,6 +423,27 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, > mid = (low + high) / 2; > } > > + /* > + * The conversion code granularity provided by the table. Let's > + * assume that the relationship between temperature and > + * analog value between 2 table entries is linear and interpolate > + * to produce less granular result. > + */ > + num = abs(table->id[mid].code - table->id[mid + 1].code); > + num *= temp - table->id[mid].temp; > + denom = table->id[mid + 1].temp - table->id[mid].temp; > + > + switch (table->mode) { > + case ADC_DECREMENT: > + return table->id[mid].code - (num / denom); > + case ADC_INCREMENT: > + return table->id[mid].code + (num / denom); > + default: > + pr_err("%s: invalid conversion table, mode=%d\n", Is this really an invalid conversion table, or an invalid conversion mode? > + __func__, table->mode); > + return error; > + } > + > exit: > pr_err("%s: invalid temperature, temp=%d error=%d\n", > __func__, temp, error); > -- > 2.7.4 >
Hey, On Mon, Nov 28, 2016 at 07:12:03PM +0800, Caesar Wang wrote: <cut> > + num = abs(table->id[mid].code - table->id[mid + 1].code); > + num *= temp - table->id[mid].temp; > + denom = table->id[mid + 1].temp - table->id[mid].temp; isn't the above 'mid + 1' off-by-one when mid ends being == table.length - 1? You would be accessing table->id[table.length], which is wrong memory access, no?
在 2016年11月30日 14:29, Eduardo Valentin 写道: > Hey, > > On Mon, Nov 28, 2016 at 07:12:03PM +0800, Caesar Wang wrote: > > <cut> > >> + num = abs(table->id[mid].code - table->id[mid + 1].code); >> + num *= temp - table->id[mid].temp; >> + denom = table->id[mid + 1].temp - table->id[mid].temp; > > isn't the above 'mid + 1' off-by-one when mid ends being == table.length - 1? > > You would be accessing table->id[table.length], which is wrong memory > access, no? Yup, that's indeed a real issue for me. FIxes on next version. Thanks. -Caesar > > > _______________________________________________ > Linux-rockchip mailing list > Linux-rockchip@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-rockchip
diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c index ca1730e..660ed3b 100644 --- a/drivers/thermal/rockchip_thermal.c +++ b/drivers/thermal/rockchip_thermal.c @@ -401,6 +401,8 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, int temp) { int high, low, mid; + unsigned long num; + unsigned int denom; u32 error = table->data_mask; low = 0; @@ -421,6 +423,27 @@ static u32 rk_tsadcv2_temp_to_code(const struct chip_tsadc_table *table, mid = (low + high) / 2; } + /* + * The conversion code granularity provided by the table. Let's + * assume that the relationship between temperature and + * analog value between 2 table entries is linear and interpolate + * to produce less granular result. + */ + num = abs(table->id[mid].code - table->id[mid + 1].code); + num *= temp - table->id[mid].temp; + denom = table->id[mid + 1].temp - table->id[mid].temp; + + switch (table->mode) { + case ADC_DECREMENT: + return table->id[mid].code - (num / denom); + case ADC_INCREMENT: + return table->id[mid].code + (num / denom); + default: + pr_err("%s: invalid conversion table, mode=%d\n", + __func__, table->mode); + return error; + } + exit: pr_err("%s: invalid temperature, temp=%d error=%d\n", __func__, temp, error);